Model
We postulate that before walking into our store, consumers have a list (mental if not on paper) of products that they intend to purchase. Consumers also have a PRIOR for each of these SKUs they plan to purchase and possibly an expected price related to purchasing from outside stores. During the purchasing process, a dis-confirmation between PRIOR and current price may generate psychological gain or loss (transaction utility). Further, after observing the current price, consumers may update their expected price of purchasing from outside stores, which is the POST we collect after participants finish the shopping process. Consumers may also update their price expectation for the next shopping trip in our store, which will be the PRIOR we collect in the next week.